Metafilter was still very definitely in its nascent stages. Given how slow the discussion was and the quality of the links, I wonder how people would have been attracted to the site. There were several posts on some days; on other days, maybe one. Some days none.
The participants are mostly mathowie and grant. Most of the posts are marginally interesting single-links, and the majority of the posts do not have any comments or discussion. The posts are heavily weighted to "new" computer technologies or updates which are utterly archaic to the modern reader. Apparently user honeyman didn't find Metafilter terribly interesting, as the user made two comments on back to back days and never came back again.
Here are some highlights to 300's
In 301, Matt posts a guide to e-mailing and lets the world know that he was receiving 150-200 emails a day. In 1999, that was surely quite a bit. Matt let us know more about his e-mail box in post 356 (a self-link) where he lets us know that he has 74 useless emails in a month. In 2006, 74 spam mails in a month would be terrific for most internet aficionados.
In 303, there is a discussion about .pdfs with mathowie and grant praising the potential for .pdfs. As the years advance, Matt's appreciation for .pdfs has apparently waned.
In 304, a post about fonts that was botched, mathowie makes mention of including "edit functionality" to Metafilter. Interestingly, the request for edit functionality is still one of the most requested features at Metafilter to this day.
Post 316 is the most popular post in the 300's in terms of discussion with a whopping 5 comments.
There is a blatant self-link by #1 himself in post 327 (and 356 by mathowie and by user grant in 309) in which he links to an article he has written and his own site with a mirror of the article. Today, such a post would be in Metatalk under the category Metafilter-related. But it would be bannable for a poster to link his own article.
In post 348, we see the first incidence of what could be called a meme or fixation of Metafilter. Matthowie posts about Bill Hicks, someone who is frequently memorialized and lauded on that site.
376 appears to be a double post (of sorts) by mathowie of post 346. If it was a double by #1, it was not deleted.
mathowie links to fark.com again at 386. Fark is persona non gratis on Metafilter these days, but Matt linked to the main site himself several times in the early days.
In 391, some fresh faces appeared that still participate today: jonmc and riffola. A post about music from jonmc should not surprise anyone. jonmc has been one of the most extensive participants at Metafilter, and music is frequently his topic of choice.
All in all, there is little of interest to be found in the 301-400 posts at Metafilter. The conversation is virtually non-existent. The posts are primarily by mathowie or grant. The posts are mostly single-links to technology news or tech-related observations.
But it trudged on.